The sights include : The Bracken Bat Cave in Comal County, Rock and Petrified Wood Hunting North of Giddings, TX and My Biology Term Paper on the Mexican Free-Tail Bats of Texas.
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Forward : Did you have your fill of Wendish Noodles from Last Time? Not me, I'm still hungry. Due to a very busy Summer school schedule, I still have not been able to travel a lot. Although it is a first-come-first-serve type of an arrangement, it took me three years, to finally be invited to witness the bat emergence of Bracken cave in Comal County this month by Bat Conservation International. I even missed my little niece's birthday over this event. Therefore, this month's report will cover this emergence and then present a term paper I wrote on the Mexican Free-Tail bats of Texas. On the way home from San Antonio, I made a quick stop just north of Giddings, TX for a little rock and petrified wood hunt which I will also discuss. So, sit back and enjoy the show! Star Date : 07/15/2006 - Saturday Yep, it was another very early morning rise, but not to get an early start on the road. No!!! I had a 9:30 am mid-term at U of H for my on-line Cultural Psychology class. The exam was a piece of cake, so forty five minutes later, I was finally on the road to San Antonio. The Bracken Bat Cave is actually just northeast of San Antonio right by Natural Bridge Caverns! I was hoping it would be a non-eventful drive, but unfortunately in Katy, while driving west on I-10, all of us drivers were forced to merge from four lanes to one. I wonder why? That traffic jam probably set me back a good 30 minutes. Other than that, the drive went well and I made it to my Aunt Kathy's and my Uncle's Tom's place with plenty of time to spare. Thus, I spent the next few hours visiting with them and studying for my Calculus test on Monday. Of coarse Kathy had to show me her new car. Kathy then fed us and when 5:30 pm rolled around, it was time for Tom and I to hit the road to the BAT CAVE Robin! Um, I mean Tom.... Please note, if you are ever invited to the emergence, there is a road out there called "Bat Cave Road". Bracken Cave ain't on it. Stay on CR or RR 3009 and the cave will be be to your left just before the turn-off to Natural Bridge Caverns. Just watch for the signs. First, a quick note on the Bracken Cave and Bat Conservation International, Inc. or BCI for short. Bracken Cave was acquired by Bat Conservation International 1992 to ensure this critical bat maternity roost for Central Texas' Mexican free-tailed bats (Tadarida brasiliensis) is permanently protected. Bat Conservation International (BCI), is an organization based in Austin, Texas, is devoted to conservation, education, and research initiatives involving bats and the ecosystems they serve. It was founded in 1982, as scientists around the world became concerned that bats essential to the balance of nature and human economies were in alarming decline. Under the founding guidance of Dr. Merlin Tuttle, an internationally recognized authority on bats, the organization has achieved unprecedented progress by emphasizing sustainable uses of natural resources that benefit both bats and people. Please visit their website below : Bat Conservation International, Inc. The Bexar County Grotto, the San Antonio-based chapter of the National Speleological Society, is one of many caving groups across America that contribute greatly to the conservation of bats. Grotto members, by volunteering thousands of hours of loving care for Bracken Cave, are playing a vital role in helping BCI protect and manage the world's largest bat colony. Please visit their website below : The huge bat population has packed the cave with guano, which has been mined intermittently since 1856 for fertilizer and as a component of 19th century gunpowder. Two historic buildings associated with the guano miners were on the verge of collapse when BCI bought the property. Bexar County Grotto teams went to work with their own materials in 1993 to restore the dilapidated structures. First, they restored a Civil War-era guano storage shed, a task that began with wrestling the old framework back into an upright position with jacks, winches, and people power. Then the cavers replaced, and carefully matched, support posts, ceiling beams, and roof. After months of work, the once-dilapidated structure was restored to become an historic landmark - one of the oldest wooden buildings remaining in Texas. Then the volunteers went after a battered old bunkhouse, making extensive repairs to windows, doors, siding, and foundation. They even recreated metal hinges, door pulls, and window hardware to match the original style. In addition to the restoration of the property's original structures, the volunteers also built state of the art facilities for when you need to go. We finally arrived and waited for any others to arrive. We then formed a convey and slowly headed to the parking/reception area. There, we were lectured to on the do's and don'ts while observing the emergence such as no smoking, the history of the cave and the usual bat preservation speech. Interesting, why is there a bat house here when there's a nice cozy cave nearby? I think the pole for their bat house should have been a bit taller. Then, all of the sudden, the first wave of bats flew overhead. Heck, it's show time! We then took a short hike along a path to the first viewing area just above the cave entrance, armed our cameras and began the customary chants of the uh's and ah's as we witness the bat's emergence into the Texas Hill Country skies. Bat Emergence 1st Shift - Photo 1 Bat Emergence 1st Shift - Photo 2 Well, that was a short one. We were then told that the bats would emerge on and off like this for several hours so, the show would go on. While waiting on Act II, Tom and I along with several others blazed through the Mule Trail which took us to the other side facing the the cave entrance. We then listen to a Q & A session with some of the members of the BCI organization and finally learned what made these caves! At the same time, the Bracken Cave gift store was open for business so make sure you bring your money when you come out here. All proceeds from the store go to the maintenance of the bat cave and property around it. Look! Up in the sky. It's a bird, it's an airplane. No, it's time for Act II of the bat emergence. Click on the links below : After the bat emergence of Act II was over with, Tom and I headed back to the first observation site since we were told we could get some really cool sunset camera shots there. Bear in mind that this preserve is refuge to many other kinds of wildlife. Remember, the Natural Bridge Wildlife Ranch is just next door. While waiting, one of the BCI volunteers entertained the kids with some really cool stick-like insects that he found. Finally, Act III of the bat emergence began and I manned my camera. Click on the links below for some cool sunset shoots : I found this really good web page that had some very good photo's of their experience, plus some video on the Bracken Bat Cave emergence. See the link below : Jackson's Resources - Bracken Bat Cave Just in case the site disappears in the future, here is the video of the bats and their radar signatures from their site : The Bracken Cave Bat Emergence : (Real Player Required) The Bracken Cave Bat's Radar Signature : (Real Player Required) Get Your Real Player Here for Free I hope you enjoyed the information on Bracken Cave, Bat Conservation International, Inc. and the photos of the bat emergence. Now, for my term paper from last semester's Biology class. I did re-edited it to match the format of this site so, enjoy!!!
Introduction : In the state of Texas, bat viewing has become a part of the summer time vacation experience as much as watching a baseball game, visiting one of the many of the traditional amusement/theme parks and as well as visiting the numerous state and national parks for camping trips. This new craze in summertime entertainment is all thanks to the migrating Mexican Free-Tail bat. In some cases, the viewing of the nightly emergences can be likened to a rock concert. The crowds can be quite big with the usual sortie of street characters bouncing about, security/police maintaining order and enjoying the carnival-like atmosphere complete with food and trinket venders. The festive activity and all the people watching makes for a great warm-up experience for the light show to follow. As the bats begin their emergence, they create awe inspiring images with their silhouettes against the sunset and white clouds above. Figure 1. notes such experiences. At other times, the Free-Tails’ emergence, can be much more of an intimate experience when viewed with smaller groups in the remote regions of the Texas Hill Country and Texas Panhandle Canyon areas. During these times, the experience can be quite relaxing and tranquil while one enjoys the silhouetted patterns against the sunset. It is also sometimes a chance to bare witness to Mother Nature’s harsh realities of life and death while the bats dodge hawks, raccoons and the snakes. Whatever the experience may be to the viewer, it is also important to understand their role in nature, their life cycle and the mutual benefits we both receive and give back to our furry communities of the night skies. The discussion that follows will include the Free-Tails’ life cycle, their habitats, and their role in the food chain. Additionally, the Free-Tails’ migration patterns, misconceptions and their benefits to mankind will be also be addressed. Finally, a list of bat emergence locations will be presented so that the reader may experience the new summertime craze in a Texas vacation.
Etymology : There is quite a variety of bats who call their home Texas, even if its only for the Summer. Therefore, a description of the Free-Tail being discussed here needs to be addressed first, since many other species of bats co-habitat with the Free-Tail. First, it’s confusing name. If one speaks to any bat enthusiast in Texas, they’ll call this species by its more common name, the “Mexican Free-Tail” bat. However, in view of the name’s etymology, it should be realistically be called the “Brazilian Free-Tail” bat. Tadarida – Latin for : Withered Toad And Brasiliensis – Latin for : Belonging to Brazil There is actually (2) sub-species of Tadarida Brasiliensis. The first sub-species is T. b. cynocephala, a non-migratory species which inhabits the eastern piney woods of the state and the T. b. mexicana which is the migratory species being discussed. To make things even more confusing, there has been a recent discovery of a species that is intermediate between the two sub-species found near Navasota in Grimes County. Biologists from Texas A&M University believe that this new species is from inbreeding of the T. b. cynocephala and T. b. mexicana. [Wikipedia-Tadarida]. Thus, we see in Table I, its scientific classification:
Table I. Scientific Classification of the Mexican Free-Tail Bat. Now that the name has been cleared up, this discussion will turn to its appearance which will be used in its identification and distinction from other Texas species of bats. Appearance : The wings of the Mexican Free-Tail bat are long and narrow. The bat’s tail runs through its tail membrane and extents one third further out. Thus, their name, their lower half of their tail is free from its back membrane. Their fur during a new molt is gray which then turns to a rusty brown. Relative to the size of their skull, they have large rounded ears and wrinkles above their mouths. This is a medium size bat with a forearm of 1.5 to 1.8 inches (38 – 46 mm) and a wingspan of 11.3 to 13.4 inches (287 – 340 mm) long. It’s head-to-body length is (85 – 100 mm) and it has a tail length of (40 – 55 mm). The bat’s average weight is around 11 – 15 grams. See Figure 2. [Tuttle] Figure 2. The Mexican Free-Tail Bat. Mating and Rearing Young Pups : Due to its widespread occurrence and abundance, much is known of this particular bat and it has been highly studied. First, this species of bats lives in colonies. While in Mexico or Brazil, the males and females of the colony mate during the months of March and April. Occasionally, the females may carry up to two embryos. Soon afterwards, the colony begins its migration north to Texas and New Mexico. The gestation period lasts approximately 11 weeks. Although the males play no part in the rearing of the young pups, this length of pregnancy, yields plenty of time for the colony’s migration. Incidentally, the bats migrate to the same roosting site every summer. Peak birthing of the colony occurs around mid-June. Seventy percent of the young pups in a colony are born within ten days. Once the pups are born, they weigh in at approximately 2.5 grams and are blind, naked and pink in color. The nursing colony, in which they are kept, is in a separate area of the adult roosting site and may contain over a million pups. Due to the high concentrations of pups in a single area of the roosting site, it was first thought the mother made no attempt to locate and nurse her own young and only nursed a few pups they happened to come upon by chance. However, recent studies have shown that the mothers do indeed recognize and nurse their own through all of the confusion of millions of chirping pups. [Schmidly] Maturation and Life Span : By six weeks, the pups have gown to the point of harnessing flight and hunt on their own. At this point, they now join the others in the main roosting chamber. After one year, females have reached sexual maturity and may become pregnant at that time. As for the males, they do not reach sexual maturity until about a year and a half to almost two years. The life span of a Mexican Free-Tail bat is around 15 years. During that time, the bat will continue to migrate back and forth and consume 10 tons of insects per night per one million bats. Although they are the predators when it comes to the insect they consume, they themselves are the prey when it comes to the owls, hawks and other raptors who they share the skies with. Also, many bats fall prey to skunks, raccoons, opossums and snakes waiting for them at the bottom of cave entrances if they should fall due to a crash with another bat or a wall of their roosting cave during their emergence. [Schmidly] The Mexican Free-Tail Migration Patterns :
Thus, the Free-Tails begin their migration to their winter homes in Mexico and Northern South America where the insects are plentiful. [Madero] Mexican Free-Tail Habitats : Mexican Free-Tail bats roost in a whole range of structures. These normally include the caves of the Texas Hill Country and New Mexico. However, abandoned, man-made structures serve as their homes as well. These structures include : old train tunnels, bridges, abandoned mine shafts and even old abandoned buildings as well. Figures 4, 5 and 6 illustrate these structures in bat use today.
Echolocation : The old cliché, “Blind as a bat”, is actually far from the truth. Bats can see fairly well, their hearing is much better. Therefore, many species of bats employ echolocation, a type of sonar. Not all bats utilize echolocation, but the Mexican Free-tail bat does. Echolocation is the process of the bat producing a very high pitch sound from a few times per second to 200 times per second. The sound produced is at a frequency which is inaudible to human ears. The bats then listen to the echoes produced from the sounds that bounce back off of objects. By analyzing the returned echoes, the bat can analyze the exact location of an object as well as the size and speed of moving objects such as insects for prey. Echolocation also prevents them from crashing into objects while in flight. Since the echolocation sounds produced by the bats and those sounds echoed back are at a frequency higher than what humans can here, devices known as bat detectors are employed to lower the frequency to levels so as to be heard by the human ears. [National Parks Conservation Association] Bat Misconceptions : We have all grown up and learned various misconceptions of bats. Unfortunately, many of theses misconceptions have led to the Mexican Free-Tail’s demised. This has resulted in the bats not only loosing their habitats, but also their lives. One major bat misconception is that all bats have rabies. Nothing could be further from the truth. In fact, only less than ½ % of bats carry the rabies virus. Fewer than 40 people actually have contracted rabies from bats in the past 40 years. [Organization for Bat Conservation] Another major misconception is that bats get tangled in people’s hair. Bats can fly very close to someone if they are very near the insects they are preying on. However, because their echolocation is so acute, they can avoid obstacles no wider than a thread. How about the “Bats suck your blood” misconception? There are bats found in Mexico, Central America and South America who are known as the Vampire bat who do feed off of blood from horses and cattle. However, the bats do not suck the blood out of their victims; they simply make a cut in their victim’s skin with their razor sharp teeth and lap the blood with their tongues. The Mexican Free-Tail Bats are of coarse carnivores of insects, insects who are a pest to the crops of the farmers just south of the Texas Hill Country. The belief that bats are rodents may be a very surprising misconception. There is recent evidence that bats may be more genetically related to primates, which includes humans, than the typical rodent. Finally, “Bats are blind”. Although bats do not see in color, they do see quite a bit better than humans do, especially at night. Additionally, their echolocation features allows them even further perceptions to their environment. [Harvey] The Free-Tail’s Benefits to Mankind : Bats have an enormous benefit to man’s society, especially to the agriculture industry. Every evening, a Free-tail bat consumes two-thirds of its own body weight in insects. Its main course includes the moths that migrate to the north and feed upon the Midwest corn fields. Of coarse that also includes the moths who feed upon both the south-central and Panhandle cotton fields. Therefore, they act as natural pesticides by cutting down the need for south-central farmers’ use of chemical insecticides. Mosquitoes are another insect on the dietary list of the Free-Tail Bats. Their help in keeping the mosquitoes population in check also reduces the risk of infectious diseases such as West Nile Disease. BCI, Bat Conservation International, warns
that shrinking bat populations may increase the need for chemical pesticides,
which can be harmful to entire ecosystems. Although the Mexican Free-Tail bat feeds upon insects, their fruit eating cousins, help to pollinate plant species. This is extremely helpful for plants that only flower at night such as several species of cacti. [Wild Western North Carolina] Conclusions : With 58 different species of bats living in the United States, many thanks should go to the Mexican Free-Tail bat colonies of Central Texas and New Mexico. Although the Free-Tails support our ecosystems through insect control, their other bat cousins play vital roles in plant pollination. Bats benefit humans far more than they endanger them and shrinking bat populations may increase the need for chemical pesticides, which can be harmful to entire ecosystems. So bats are not the vicious creatures we know from old misconceptions and perhaps it wouldn't be so bad to befriend a bat. Texans are indeed, a very lucky people to have so many numerous bat colonies spread throughout their great state. Therefore, find a bat emergence area near you. Enjoy the interesting show they produce while knowing they are also benefiting our piece of the world. Free-Tail Bat Emergence Locations for Viewing : The following sites are areas in which the public can view the emergence of the Mexican Free-Tail bats. Clarity Tunnel :
Carlsbad Caverns :
Big Bend National Park (The Mariscal Mine Shafts) :
The Stuart Bat Cave at Kickapoo Caverns State Park :
The Devil’s Sinkhole State Natural Area :
The Frio River Cave :
The James Eckert Bat Cave of Mason County :
The Old Tunnel Wildlife Management Area :
Bracken Cave in New Braunfels :
Congress Avenue Bridge :
The Selah Bamberger Ranch :
List of References : (I must give give credit, where credit is due. If the references bore you, then please just scroll down for the rest of the story.) Bamberger Ranch Preserve – The Bats of Selah. Web Address : http://www.bambergerranch.org/facilities/bats.phtml#folly . Bat Conservation International – A Little History. Web Address : http://www.batcon.org/home/index.asp?idPage=122 . Carlsbad Caverns National Park – The Bat Flight Program. Web Address : http://www.nps.gov/cave/batprog.htm . Conservation International – Bracken Bat Cave and Nature Preserve. Web Address : http://www.batcon.org/home/index.asp?idPage=56&idSubPage=75 . Harvey, Michael J. (September 7, 1999). U.S. Fish and Wildlife Service – Common Misconceptions About Bats. Web Address : http://www.fws.gov/endangered/bats/miscon.htm . Hill Country Nature Tours – Sunset Bat Flight. Web Address : http://www.hillcountryadventures.com/sunset_bat_flight.htm . Madero, Alida. (2003). The Wild Ones Animal Index – Mexican Free-Tail Bat. Web Address : http://www.thewildones.org/ . National Parks Conservation Association – Bats, Echolocation. Web Address : http://www.npca.org/wildlife_protection/wildlife_facts/bats/echolocation.asp. Nature Conservancy, The – Eckert James River Bat Cave Preserve. Web Address : http://nature.org/wherewework/northamerica/states/texas/preserves/art6022.html . Organization for Bat Conservation – Bats and Human (Rabies). Web Address : http://www.batconservation.org/content/batsandhumans/batsandhumans.htm . Oswald, Diane. (May 13, 2004). Texas A&M University - Fangs for the Memories : Bats Should be Thanked, not Feared. Web Address : http://www.tamu.edu/univrel/aggiedaily/news/stories/04/051304-4.html . Schmidly, J. David. (1991). Family Molossidae – Brazilian Free-tail Bat. The Bats of Texas, (pp. 149-153). College Station: Texas A&M University Press. Texas Parks and Wildlife Department – Cap Rock Canyons State Park and Trail Way. Web Address : http://www.tpwd.state.tx.us/newsmedia/calendar/?calpage=s0023 . Texas Parks and Wildlife Department – Devil’s Sinkhole State Natural Area. Web Address : http://www.tpwd.state.tx.us/spdest/findadest/parks/devils_sinkhole/ . Texas Parks and Wildlife Department – Kickapoo Caverns State Park. Web Address : http://www.tpwd.state.tx.us/spdest/findadest/parks/kickapoo_cavern/act.phtml . Texas Parks and Wildlife Department – Old Tunnel (WMA). Web Address : http://www.tpwd.state.tx.us/huntwild/hunt/wma/find_a_wma/list/?id=17.&activity=wildlifeViewing . Tuttle, D. Merlin. (2003). Mexican Free-Tail Bat. Texas Bats, (pp. 65-67). Austin : Bat Conservation International. Wild Western North Carolina – Naturalist Notes (Bats : Let’s Dispel the Myths!). Web Address : http://www.wildwnc.org/natnotes/batmyths.html . Wikipedia – Tadarida. Web, Address : http://en.wikipedia.org/wiki/Tadarida Star Date 07/16/2006 - Sunday and Giddings's Rocks and Petrified Wood Although I slept in, I spent the morning getting ready for the trip back. I packed up the car and thanked Tom and Kathy for their hospitality once more. This time, I took I-35 north and then took Hwy 21 to Hwy 290. From Hwy 290, I traveled east to Giddings, TX. Then in Giddings, I took Hwy 141 north and hit the unpaved county roads to investigate them for interesting rocks and petrified wood. You didn't think you were going to get away without hearing about another rock hounding trip, did you? I got the idea for hunting in this area off of the discussion boards of : The first stop was on PR 1414. The GPS coordinates for this site where it meets the highway are : North 30° 13.308' and West 96° 53.200' I searched the dirt road and was quite successful in finding the treasures in the sandy dirt of the road. Unfortunately, I did not realize at the time that "PR" stands for "Private Road" and I do not recommend anyone to hunt on it out of respect for the residents there. However, there were quite a few homes along the road there and no one really bothered me. They probably thought I received permission from one of their neighbors. My next stop was off of CR 117. The GPS coordinates for this site where the road meets the highway are : North 30° 14.215' and West 96° 51.912' Again, all along the road, I was successful in finding material to feed my rock tumblers. My last stop was off of CR 121. The GPS coordinates for this site where the road meets the highway are : North 30° 16.232' and West 96° 49.003' Again, this road was typical of the other two, however, my searching for interesting agates, jaspers and petrified wood was not as successful as the first two sites. I did manage to pick up a bucket load and the following are some photos of the gems after I pulled them out of the ole' tumbler : Giddings's Rocks and Petrified Wood - Photo 1 Giddings's Rocks and Petrified Wood - Photo 2 Giddings's Rocks and Petrified Wood - Photo 3 Giddings's Rocks and Petrified Wood - Photo 4 For more information on this site, please see the Texas rock hunting link below : Giddings Petrified Wood and Rocks After this brief hunt, it was time to hit the road again. After all, I had that Calculus test to study for on Monday. I returned to Giddings and took Hwy 290 east back to Houston, then the ole' Belt Way 8 south to Hwy 288 and back home to Lake Jackson. I already miss that great Texas Hill Country and can't wait to go back. Aftermath : Well, that's one more Texas bat emergence site I can add to my list of having been visited. I still need to visit the Bamberger Ranch and the McNeil Road overpass on I-35 in Round Rock, TX. During the bat emergence at Bracken, the folks at BCI stated that the best location for viewing the emergence would be on the east side of I-35. Also, they stated that the owners of a business at that corner reserved a small observatory area at that location. I realize that my term paper included the misconception that all bats carry rabies and that only less than 1/2 % could be carriers. Recently in the Houston area, a couple of kids played around with some sick bats and contracted rabies. One child even died from the disease. Therefore, if found, all bats should be treated with caution to be safe and not sorry. Unfortunately, here in Lake Jackson, we are experiencing quite an epidemic with bats with rabies here. Fortunately, the bats have been found and the residents of Casa Del Largo apartments are being moved to other housing facilities. Please see the link below : The Rabid Bats of Lake Jackson, TX A Follow-Up to the Above Story Well, the Saga Continues...... (At least they get a new home.) I haven't made any new wire wrapped jewelry since my last report due to the lack of free time I have right now. However, I scrounged around and thought I would try to work on some future projects with some small polished ammonites, orthoceras', knapped obsidian and crystal quartz points and some jewelry grade trilobites. If I ever get my on-line store up and running, I'll let you know!
Lastly, I just finished my Art History term paper on the Indian Rock Art of Paint Rock, TX. Expect that to be presented for the next time around. FYI, It's up!!! See my new on-line Jewelry and Gift Shop link below :
So until next time, take care and I'll See you, on the road!!! Francis
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Copyright © 1999 by [The Texas Road Runners - Francis Kiefel]. All rights reserved.
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